Combining Texts

All the ideas for 'Introduction to Mathematical Logic', 'On Referring' and 'Introduction to 'Self-Knowledge''

expand these ideas     |    start again     |     specify just one area for these texts


33 ideas

4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
Post proved the consistency of propositional logic in 1921 [Walicki]
Propositional language can only relate statements as the same or as different [Walicki]
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
Boolean connectives are interpreted as functions on the set {1,0} [Walicki]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
The empty set is useful for defining sets by properties, when the members are not yet known [Walicki]
The empty set avoids having to take special precautions in case members vanish [Walicki]
4. Formal Logic / F. Set Theory ST / 6. Ordering in Sets
Ordinals play the central role in set theory, providing the model of well-ordering [Walicki]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
To determine the patterns in logic, one must identify its 'building blocks' [Walicki]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
There are no rules for the exact logic of ordinary language, because that doesn't exist [Strawson,P]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / c. Theory of definite descriptions
'The present King of France is bald' presupposes existence, rather than stating it [Strawson,P, by Grayling]
Russell asks when 'The King of France is wise' would be a true assertion [Strawson,P]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A 'model' of a theory specifies interpreting a language in a domain to make all theorems true [Walicki]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
The L-S Theorem says no theory (even of reals) says more than a natural number theory [Walicki]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
A compact axiomatisation makes it possible to understand a field as a whole [Walicki]
Axiomatic systems are purely syntactic, and do not presuppose any interpretation [Walicki]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
Members of ordinals are ordinals, and also subsets of ordinals [Walicki]
Ordinals are transitive sets of transitive sets; or transitive sets totally ordered by inclusion [Walicki]
Ordinals are the empty set, union with the singleton, and any arbitrary union of ordinals [Walicki]
The union of finite ordinals is the first 'limit ordinal'; 2ω is the second... [Walicki]
Two infinite ordinals can represent a single infinite cardinal [Walicki]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
In non-Euclidean geometry, all Euclidean theorems are valid that avoid the fifth postulate [Walicki]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
Inductive proof depends on the choice of the ordering [Walicki]
10. Modality / A. Necessity / 2. Nature of Necessity
Scotus based modality on semantic consistency, instead of on what the future could allow [Walicki]
16. Persons / B. Nature of the Self / 7. Self and Body / a. Self needs body
If we have a pain, we are strongly aware of the bodily self [Cassam]
16. Persons / C. Self-Awareness / 1. Introspection
Knowledge of thoughts covers both their existence and their contents [Cassam]
16. Persons / C. Self-Awareness / 2. Knowing the Self
Outer senses are as important as introspection in the acquisition of self-knowledge [Cassam]
Is there a mode of self-awareness that isn't perception, and could it give self-knowledge? [Cassam]
Neither self-consciousness nor self-reference require self-knowledge [Cassam]
16. Persons / C. Self-Awareness / 3. Limits of Introspection
We can't introspect ourselves as objects, because that would involve possible error [Cassam]
19. Language / A. Nature of Meaning / 6. Meaning as Use
The meaning of an expression or sentence is general directions for its use, to refer or to assert [Strawson,P]
19. Language / B. Reference / 3. Direct Reference / c. Social reference
Reference is mainly a social phenomenon [Strawson,P, by Sainsbury]
19. Language / B. Reference / 4. Descriptive Reference / b. Reference by description
If an expression can refer to anything, it may still instrinsically refer, but relative to a context [Bach on Strawson,P]
19. Language / B. Reference / 5. Speaker's Reference
Expressions don't refer; people use expressions to refer [Strawson,P]
If an utterance fails to refer then it is a pseudo-use, though a speaker may think they assert something [Strawson,P]